Spindle asymmetry drives non- Mendelian chromosome segregation

Takashi Akera (1) , Lukáš Chmátal (1) , Emily Trimm (1) , Karren Yang (1) , Chanat Aonbangkhen (2) , David M Chenoweth (2) , Carsten Janke (3, 4) , Richard M Schultz (1) , Michael A Lampson (5)

1 Department of Biology, School of Arts and Sciences, University of Pennsylvania
2 Department of Chemistry, School of Arts and Sciences, University of Pennsylvania
3 Institut Curie [Paris]
4 Stress génotoxiques et cancer
5 Department of Biology, School of Arts and Sciences, University of Pennsylvania

Genetic elements compete for transmission through meiosis, when haploid gametes are created from a diploid parent. Selfish elements can enhance their transmission through a process known as meiotic drive. In female meiosis, selfish elements drive by preferentially attaching to the egg side of the spindle.This implies some asymmetry between the two sides of the spindle, but the molecular mechanisms underlying spindle asymmetry are unknown. Here we found that CDC42 signaling from the cell cortex regulated microtubule tyrosination to induce spindle asymmetry and that non-Mendelian segregation depended on this asymmetry. Cortical CDC42 depends on polarization directed by chromosomes, which are positioned near the cortex to allow the asymmetric cell division.Thus, selfish meiotic drivers exploit the asymmetry inherent in female meiosis to bias their transmission.

Domaines: Sciences du Vivant [q-bio]; Biologie cellulaire; Organisation et fonctions cellulaires [q-bio.SC]; Biologie de la reproduction

Takashi Akera, Lukáš Chmátal, Emily Trimm, Karren Yang, Chanat Aonbangkhen, et al.. Spindle asymmetry drives non- Mendelian chromosome segregation. Science, 2017, ⟨10.1126/science.aan0092⟩. ⟨hal-02376051⟩